Universal float inclinometer



Oct. 11, 1949. L. K. PERRY 2,484,730

UNIVERSAL FLOAT INCLINOMETER Filed Aug. 2l, 1945 2 Sheets-Sheet 1 INVENTOR.

A TTOP/VEY ll ni u,

lll/ll Oct. 11, 1949. 1 K. PERRY UNIVERSAL FLOAT INCLINOMETER 2 Sheets-Sheet 2 Filed Aug. 21, 1945 l IA Il 6 4 Y Y 2 0 N 5 5 .EE m w 5J mf m K 6 5 2 Y l, B m ab. /M O O 0 ,/f 3 D w www/ VM IM .f liT u i fil m. ,I /a a 9/ 3 /9 9 O O Patented Oct. 11, 1949 UNITED STATES PATENT Y`OFFICE UNIVERSAL FLOAT INCLINOMETER Leslie K..Perry, Las Vegas, Nev.

Application August 21, 1945, Serial No; 611,860

9 Claims.

This invention relates generally to the art of navigation, and` more particularly to instruments for indicating fore and aft as well as lateral deviation of a vehicle such as an aircraft, from a level, straight course.

An object of thisginvention is to provide a navigating instrument of. simple, rugged and comparatively inexpensive.,construction, which is structurally characterized by dependable, positively acting mechanism for accurately indicating climbing and diving movements of an aircraft aswell as lbanking and rolling movements thereof.

A furtherobject of this invention is to provide an automatic horizon instrument of the above described character, particularly adapted, although not necessarily, for use on light aircraft, or for auxiliary equipment to supplement present equipment on large aircraft, which is a self-contained, independent unit requiring no external source of power for its operation such as vacuum or electricity which may fail structurally or .fbe rendered useless in combat.

Still another object of this invention is to provide anautomatic horizon instrument which embodies a ball oat operating in a liquid-containing chamber with but a negligible frictional contact therebetween, and operatively connected to an indicator for actuation of the latter in accordance with such movements of the aircraft in ight as would tend to rotate the ball float about its center, to the-end of indicating to the pilot the exact relation of the aircraft both longitudinally and laterally, to level flight on a straight course.

With these and other objects in view, the in- Ventionv resides in the combinations, arrangements andl functional relationships of elements asset forth in the following specification and particularly pointed out in the appended claims.

In the accompanying drawings,

Figure 1 is a view in front elevation, showing one form of automatic horizon instrument em bodying this invention;

Figure 2 is an enlarged vertical sectional View taken on the line 2 2 of Figure 1;,

Figure 3 is a horizontal sectional View taken on the line 3 3 of Figure 2;

Figure 4 is a vertical transverse-sectional view taken on the line 4 4 of Figure 2;

Figure 5 is. an enlarged fragmentary detail sectional View of a luidvseal embodied inthe invention; and' Figure 6 is a. fragmentary detailisectional view` 2 illustrating an'adjustable balance weight and coacting calibrations for the-ball float.

Referring specically to the drawings, the inventionin itsfillustrate'd embodiment comprises a case designated` generally at C and composed of a float chamber II)v and an indicator chamber II separated by a transverse wall or partition I2. The float cham-ber' is spherical and is divided diametrically by two semi-spherical portions I3 and I4 of thecase, with the portion I3 projecting from one side of the partition I2. The two portions are secured together by bolts I5 (Figure 1) passing. through mating peripheral flanges I6 and I l, to clamp the portions together with a fluidtight joint therebetween.

The indicator' chamber II is formed by the Wall I2 and by an annular wall I9 externally threaded at 20 to receive a retaining ring 2| in which is tted against radial and axial shoulders 22 and 23, a` transparent face or cover composed of two disks of' clear glass 24 and 25 between which is interposed a disk of plastic or celluloid 226 having perpendicular and horizontal crossiffhairs 21V-and 28 (Figure 1) extending diametrically in intersecting relation to the periphery of -rthe :diskvforl co-action ywith a movably mounted dial D controlledi by a oat F in the chamber I0 in ay manner to be later fully described. The disposition of the disks 24, 25 and 26 ,'circumferentially:withrespect to the case C is Xe'd iby a .pin' 29 inthe wall. I9 of the latter entering notches '30 in the disks as shown in Figure 4.

The YoatF comprises a generally spherical body,35 ofebalsa or yother light wood or fluidtight hollow sheet metal of an outside diameter somewhat less than the diameter of the chamber to provide a fluid space 36 therebetween. At equallyaspaced intervals around the body are bearing projections 3l semi-spherical in form andadapted to freely contact the sphericalsurface of the chamber I0 with minimum friction ywhich'is reduced to a negligible quantity fby lling all otherwiseunoccupied space in the chamber I 0iwith1aliquid1 38- such as brake fluid of the types disclosed in- U..;S.` Letters Patent Nos. 1,525,942 and 1,891,962, iso-that the coefficient 0f friction v.between the float and wall of the chamber is practically nil. If constructed of wood,-the=oat F will be coated with a suitable paintatoarender vit `fluid-prooi? and resistant to the deterioratingaction of :the hydraulic brake fluid.

' At; substantiallyY itsl'nghest; point, the chamber I0 `isgfprmiided, with an inlet opening 39 into which is screwed a nipple 40 projecting from the bottom of an expansion chamber il to support the latter on the case Cv as shown in Figure 2. The expansion chamber 4| is provided with a removable filling plug 42 containing a suitable ball check valve 43 which prevents loss of fluid, yeti permits circulation of .air so as to prevent the building up of pressure in the oat chamber. The indicator chamber is provided with a suitable airiltering' vent 44 to' compensate for atmospheric pressure variations. Y

The float F is operatively connected to theA A dial D by mechanism comprising a motion trans-` v ferring element in the form of a shaft `L adaptedto provide a lever of the first class composed of a fulcrum ball 45 and co-aXial cylindrical arms* 46 and 41, the ball 45 being mounted in a socket bearing 48, onehalf of which is formed in the wall I2, and the other half in a plate 49 secured?.l

to the wall I2 by bolts 5@ having nuts 5|, so as to mount the shaft L with its arm 46 projecting into the chamber l0, and its arm 41 projecting into the chamber A fluid seal S hasa bellows portion 52 sur rounding the arm 46, and a sleeve portion 53 through which the arm 46 projects. From the bellows portion projects a disk portion |54 with'` which a clamping disk 55 and the bolts 50 co-act to secure the seal Sito the wall |2 with a fluidtight joint therebetween; The sleeve portion 53 is provided internally with annular grooves 56v (Figure 5) whichfunction to trap liquid on thev arm 46 so as to co-act with the bellows portionV 52 in preventing any fluid in the chamber l0' opening in a counterweight 64 and is threaded at "65 to receive a nut 56 to rigidly secure the rod and counterweight in place. .At its lowermost point, the body 35 is provided with a screw 61 or other weight to provide ballast.I

A connector sleeve 10 is telescopically mounted on the arm 4S" and is provided'with a key 1| slidably fitting a keyway 12 in the arm to compel the sleeve to rotate with the arm, yet be free to slide axially thereon. One end of the sleeve 10 projects beyond the free end of the arm'46 and is bifurcated to receive the head 6| of the bearing rod 52. A pivot pin 13 mounted in jewel bearings 14 vin the connector sleeve 'l0 (Figure 3) passes through a diametric bore in the head 0| to operatively connect the float F to the shaft L.

A second connector sleeve 80 is telescopically mounted on the arm 41 and is provided with a key 8| slidably tting a keyway 02 in the arm to compel the sleeve to rotate with the arm, yet befree to slide axially thereon. vOne endof the sleeve 80 projects beyond the free end of the arm 41 and is'bifurcatedto receive a bronze journal hub 03 projecting from a bronze bearing plate 84,' the hub being mounted on a pin 85 projecting from the back of the dial D. A pivot pin 8B is mounted in jewel vbearings 81 '(Figure 3) in the connector sleeve 00, and passes through alined bores'in the hub 83 and pin B5 to operatively connect the shaft L to the dial D.

A bearing element 90 is mounted for rectilinear b'f'two parallel tracks 9| in the lform of roundVv rods on which the element 00 is slidable freely by means of the bearings 92 of the element l90, the rods being xed at their ends in brackets 93 secured to the annular wall I9 of the case C by bolts 94. The element is provided with an annular knife edge contact with the bearing hub 83 and with the bearing plate 84. The sleeve 80 slidably ts between the tracks 9| and abuts the back of the bearingportion 95 of the ele. ment as shown in Figure l3 for co-action with the bearing plate'84 in confining the dial D to ,i reciprocating movement parallel to the cross hair 21 and rotational movement about the axis of its pin 8,5.

The dial D is an aluminum disk and is calibrated todesignate turning and banking movements, v by a series of radial graduations |00 numbered in degrees for left and right turns designated by characters L and R respectively, at opposite sides of a perpendicular zero degree index line |0|. The dial D is'also calibrated to designate climbing and diving movements, by parallel grad-Y and so that the dial D will give a zero Vindicationwhen the vehicle is levelboth longitudinally and transversely, as under such condition the perpendicular and horizontal index lines |0| and |03, respectively, of the dial will be alined withthe respective cross hairs 21 and 28 of the case as shown in Figurel, so that the working parts of the instrument will occupy the positions shownv in the drawings.

Should the aircraft assume a climbing or diving angle, the float F will, by virtue 'of its inertia" and its practically "frictionl'ess buoyant suspension in the liquid 33 of'thefloat chamber |0, tend to maintaina fixed relation to the earth so that' the angular movement of the case C with the air` craft through the -climbing or diving angle, will cause the iioat to eiiect pivotal movement of Vthe shaft L about the axis of its fulcrum ball 45 by pivotal movement between the float and con nector sleeve 10 at the pin 13, in accordance with the angular displacement of the case C relative to the float about the center of the latter.

Through the connector sleeve 80, this motion of the shaft-L is transmitted to the dial D by pivotal movement between the latter and shaft atthe pin 8B, which causes the bearing element 90 to be moved along the tracks 9| and topositively guide the dial vertically and rectilinearly parallel to the plane of the cross hairs 21 and 28.. The spacing of the horizontal graduations |02 has been s0 calculated that they will co-act with the horizontal cross hair 28 to indicate the angle of climb or dive as the case may be. v

Similarly, banking lmovements of the aircraft willreact upon the float F kto eiect rotational movement of the shaft L about the longitudinal` axis of its arms 46-41, to correspondingly rotate the dial D about its axis, for co-action` of the dial graduations |00 with the perpendicular cross hair 21 in indicating the banking or turning angle whether right or left.

Limited combinations of climbing.or'divingV` and banking will'thus be'- caused to be indicated gastrico :,by the cofac-tioicsV ot-the=gradua-tions I 00T and H12 with the respectivexcross fhairsfZ-and 2S,-so ythat 1 therelationfoi the `aircraft.to :the :horizon-Will be .apparent tothe pilot-latfall times. ltr-will heapi preciated :that ItheE instrument will. function to z5 indicate'll degreesof 'rolling movements as well Yasia-substantial'amountV of climbing or ydiving rmovements, and'. that itwill yopera-te Vwith equal eiiciency whether inverted or :upright It -will also .beY noted that suitable buffers '9 l a l -10 `shocks -.of sudden and rapidimovem'ents of-.the

:aircraft u-pon the-instrument, whereby toprevent .damage to the-working parts vof= the instrument. Furthermora a suitable balance weight @Gamay lbeslidably-:androtatably mounted on the con- `nector sleeve 8D for co-action with calibrations;

e8lb.onthesleeve, `in adjusting the weight to .the exact position. necessary lto obtainv a zeroxin- -edicationon thee4 dial D when the instrument is linfa-.level position. A setfscrew 459cis provided ..to-secure-the-weightuin adjusted'position, and.;

lis;renderedrfaccessiblewith asuitable tool (not :-shown)-.through yan opening inthe case C normallyclosed bya screw plug H35 as shown in .'Eigure'fl In conclusion, it will be understood that `the."v

disclosure of hydraulic ffiiuid as the damping medium forthe float F to prevent the neat from n'agitatingtoo freelyg-is merely illustrative, as such fluid has -been chosen becauseof 'its freedom from Y, freezing at the low temperatures. met with 'under certain iiying conditions.

vsiIclaim:

11. In J an :instrument fof the class described, ,fmeansxdefining a spherical oat'chamber 'conftaining a'liquid 'and adapted to be fixed to a vvehicleya generally spherical .buoyant body freerlyrsuspended in said liquid'and'having peripheral bearing projections providing contact.ibetween the .wail .fof'theLchamber and the body, so as to guide the latter with negligible friction in order that the body will, by its inertia; tend to main- ..tain.axed. relation to .the earth; al graduated dialhaving an axis; meansmounting-said .dial for rotation about its axis and for rectilinear movement l transversely of l"-its liaxis; -means coacting Iwith said dial to indicate said dial'enove- ,'zments; ashaft having ball yand-socket fulcrum Vifi-termediate its ends, by which the shaftis mov- -.ably mounted from the rst means; an extensible, lpivotal connection between theshaft at oneside of its fulcrum and the body fat a location. oifset :fromitsA center; and an extensible, pivotalu connectionv between the shaft at the other side of its fulcrum, and-the dial, `by which the latter willtben'otated and/or .transversely moved in accordance with the movementsimparte'd to the fshaft by'movements of therst means relative @tov the body.

2. In an instrument of the class described, means dening a spherical float chamber containing a liquid and adapted to be iixed to a vehicle; a generally spherical buoyant body freely suspended in said liquid and having peripheral bearing projections providing contact between the wall of the chamber and the body, so as to guide the latter with negligible friction in order that the body will, by its inertia, tend to maintain a xed relation to the earth; a graduated dial having an axis; means mounting said dial for rotation about its axis and for rectilinear amovement f transversely-1 of -its axis `means-#co- -fa`ctingfwith saiddal to indicate said.dia12move `ments p arzshafthaving afballand socket fulcrum .intermediate its ends, `by-.which` theshaft is .movablymounted from the rst means ;.connectors mounted'onmthefshaftat opposite-sides of' 'its iulcrum' andfbeing-keyedfto the shaft Yfor rotation therewith-.yet -freef-to move axiallyrelativeto 'the.shaft; means pivotally connecting oneofsaid connectors tosaidfbody about an axisoffset from f the center. of the body;. and kmeans pivotally'connecting the other of ysaid connectors to said dial to rotate and/or transversely move same infac- :icordanceWithmovements imparted to the shaft :byfmovements of -the rst `means relative tolthe body lf3. rInvan instrument ofthe 'classl described, meanswdefining=a spherical float chamber con- "taining a :liquid'and adapted to be fixed to a vehicle; a generally spherical buoyant body free- .lyf suspended :in'said liquid and having peripheral bearing projections providing Contact between the .wall of the chamber and the body, so as to guide the latter with-A negligiblel friction .in order that the'body Iwill, by its' inertia, `tend to -main- .-tai-n a `xed relation to--the earth; a. graduated "-dial having a journal hub;a bearing element re- 'ceivingf saidffhub; ytracks on which said bearing element is mounted to guide the dial for .rectilinearmovement-'transversely of its axis,.yet :permit rotation-of `thedial about its axis ;Umeans co-actingwith said dial to indicate themagnitude yof the= dial movements; a shaft having af'ball and socket .fulcrum 'intermediate its ends by lwhich 'the` shaft is Amovably mounted from the -rst .Y means; -a "sleeve lconnector telescopically .vv-mounted onffthe shaft at one side of said fulcrum .and splinedfto the shaft; means pivotally connecting said connector to said body about .an axis offset fromthe center of the body; a second sleeve connectortelescopically mounted on the shaft at the other side of .said fulcrum and splined to the shaft; and means pivotally connecting said secvkond connector .tocsaid .dial hub so as to-effect Arotary `and/or transverse movements of thedial inaccordance with movements imparted'to the -shaftebymovements of -the first means relative to saidfbody.

Lin-fan :instrument-of the class described-two v`-means adapted Ato respectively represent the horizon andra` perpendicular thereto; a dial having' graduations; means rotatably mounting said ldial about-its-axis for co-action 'with said per- -penxlicularone.ofI said two-means in indicating turning.A and, banking movements; means mount- -ing saidwdialfor movement transversely vof its `axis, for `co-action with the horizon-representing -.means-in indicating climbing and divingmovefme-nts mea-ns defining' af 'spherical float `cham-ber containing -.a liquidya oatinsaid chamber having portions contacting the'chamber v"wall with ,negligiblefriction so that the float will, Vby lits -inertia,-tend-to .maintain a fixed relationv tov the earth; and means operatively connecting the float to said dial to actuate the latter rotationally or transversely according as movement of the chamber tends to rotate the float about one axis, or about a second axis perpendicular to said one axls.

5. In an instru-ment of the class described, two means adapted to respectively represent the horizon and a perpendicular thereto; a dial having graduations; means rotatably mounting said dial about its axis for co-action with said perpendicular one of said two means in indicating turning and bankingmovments; 'means' irmimting4 said dial for movement transversely of its axis, for

co-'actionwith the horizon-representing means Ain indicating climbing and diving movements;

means defining a spherical float chamber containingV aliquid; a oat in said chamber having portions contacting the chamber Wall with negligible friction so that the float will, by its inertia, tend to maintain a fixed relation to the earth; 'and means' operatively Vconnecting the float to said dial to actuate the latter rotationally or transversely according as'movement of the chamber tends to rotate the float about one axis, or

about' a second axis perpendicular to' said one chamber having horizontal and perpendicular cross hairs, and a float'chamber containing a quantity of liquid; a float in said liquid `'contactf ing the chamber Wall with negligible friction so as to 'tend to maintain,by its'inertia, a xed relation to the earth; a shaft'having a ball and socket fulcrum in said Wall and projecting from opposite sides thereof intov said chambers; al

graduated dial; means mounting said dial in the indicator chamberfor rotation to co-act With the perpendicular cross hair; 'means mounting the dial for vertical movement transversely of it-s axis 'for co-action with said horizontal cross hair; said float having a recess into which said shaft projects; means pivotally connecting said shaft in said recess to the float at aA location offset from -the center of the float; 4and means pivotally connecting said shaft to said dial, to transmit to the latter, movements imparted to the yshaft in response to such movements of the case as rotatably react upon the float. v

7. In an instrument of the class described, a case havingv a wall dividing it into an indicator chamber having horizontal and perpendicular cross hairs, and a float chamber containing 3a quantity of liquid; a oat in said liquid contacting the chamber'wall with negligible friction `so as to tend Vto maintain, by it-s inertia, a xed relation to the earth; a shaft having a ball and socket fulcrum in said Wall and projecting from opposite sides thereof into said chambers; a graduated dial having a journal hub; a bearing element in Which said hub is rotatably mounted for co-action of the dial with the perpendicular cross hair; tracks on Which said element is mounted to mount the dial for vertical movement transversely of its axis for co-action with said horizontal cross hair; means operatively connecting the shaft to the float; and ,means operatively connecting the shaft to said dial "hub to transmit to the dial, movements imparted to the shaft 'in responsev to such movements of the case as rotatably react upon the oat.

8. In an instrument of the class described, a case having a Wall dividing it into an indicator chamber having horizontal and perpendicular cross hairs, and a float chamber containing a quantity of liquid; a float in said liquid contacting the" chamber Wall with negligible friction-so as to tend to maintain, by its inertia, a fixed relation to the earth; a shaft having a ball and socket fulcrurn in said Wall and projecting from opposite sides thereof into said chambers; a graduated dial having a journal hub; a bearing element in which said hub is rotatably mounted for co-action of the dial with the perpendicular cross hair; tracks ron which said element is mounted to mount the dial for vertical movement transversely of its axis for co-action with said horizontal cross hair; said float having a recess into which one end of said shaft projects; connector -sleeves telescopically mounted on the vend portions of said shaft and having splined connections therewith; means pivotally connecting one connector sleeve to the float at a location offset from the float center; and meanspivotally connecting the other connector sleeve to the dial hub so as to transmit to the dial, movements imparted to the shaft in response to such movements of the case as to react rotationally upon the float.A

9. In an instrument of the class described,a graduated dial having a journal hub; a bearing member having spaced bearings and an annular knife edge bearing in which said hub is mounted to support the dial for rotation; tracks on which said bearing member is mounted to support the dial for rectilinear movement transversely'of the dial axis; a fixed supporthaving cross hairs disposed in front of said dial for co-action With the dial graduations in giving indications of the aforesaid movements of the dial; and means operatively connected to said hub, for actuating the dial.

' LESLIE K. PERRY.

REFERENCES CITED The following references are of record in the le of rthis patent: t 

